Authorities said the suspects threw explosives from the car as police followed it into Watertown. The suspects and police exchanged gunfire, and one of the suspects was critically injured and later died at a hospital while the other escaped. The FBI said it was working with local authorities to determine what happened. Doctors at Beth Israel Deaconess Medical Center in Boston where a suspect in the marathon bombings was taken and later died said they treated a man with a possible blast injury and multiple gunshot wounds. They wouldn't say if the patient they treated, who came in with police, was the suspect in the black hat from marathon surveillance footage. The MIT shooting on the Cambridge campus Thursday night was followed by reports of gunfire and explosions in Watertown, about 10 miles west of Boston. The MIT officer had been responding to report of a disturbance Thursday night when he was shot multiple times, according to a statement from the Middlesex district attorney's office and Cambridge police. It said there were no other victims. In Watertown, witnesses reported hearing multiple gunshots and explosions at about 1 a.m. EDT Friday. Dozens of police officers and FBI agents were in the neighborhood and a helicopter circled overhead. State police spokesman David Procopio said, "The incident in Watertown did involve what we believe to be explosive devices possibly, potentially, being used against the police officers." MIT said right after the 10:30 p.m. shooting that police were sweeping the campus in Cambridge and urged people to remain indoors. They urged people urged to stay away from the Stata Center, a mixed-use building with faculty offices, classrooms and a common area. Hours later, MIT, which has about 11,000 students, said the campus was clear but the shooter was still on the loose.